In town, with the 4.4i, driving aggressively, I get to about 300 miles on a tank, sometimes more, sometimes less. On the highway at 80mph, I get about 400 miles on the nose, and 19mpg. Towing 6000# behind me, I get about 12mpg at 75mph or so.

In town mileage with trailer has dropped to 10mpg before with lots of starts and stops, but generally I get 14-15mpg in town, and 19 on the highway. Been consistent that way for 36k miles now... :-)